A/F Ratio Gauge....NEED HELP

I purchased myself a Faze Air/Fuel Ratio Gauge this morning to compliment my Faze Boost Gauge. I have the back light wired up but I cant figure out where I have to wire in the the part that goes to the oxygen senson. Does the wiring have to go under the car because the wire that was supplied by Faze seems way too short. I am mounting the guage in the door panel where the vents used to be. The boost guage looks great there but there is a big hole where the other vent was. I also need to know where I can connect the power supply for the meter. It needs to be connected to a constant 12V source.

Youll need to connect the sensor wire to the front 02.. which on most GMs is the purple wire..i ran mine thru the firewall where i ran my boost line... for the contant 12v source find a source that comes on with the ignition..which shouldnt be that difficult.

the fuse box is right by your gauges, tap into a circuit there for 12v

I have no idea which wire to tap into theres so many.

find one that only powers on by the key..say..the radio....grap a test light an porbe the location an see if it powers on an off with thekey.